1. Field of the Invention
The present invention relates to a fluid supplying apparatus for an endoscope, and particularly relates to a fluid supplying apparatus comprising a nozzle for performing cleaning of an observation window and a jet spray aperture, and arranged so as to spray cleaning liquid from the nozzle at a desired pressure and spray a desired fluid from the jet spray aperture.
2. Description of the Related Art
Generally, as fluid supplying apparatus for endoscopes, there are lens surface cleaning devices for supplying cleaning liquid and pressurized air to an observation window provided at a distal end of an insertion portion in the event that the lens surface mounted to the observation window is soiled with body fluids or the like. As is known, the lens surface cleaning device has a nozzle opening toward the observation window, a liquid supplying passage and air passage connected to the nozzle. Also, a control valve is provided at an operating unit provided continuously from the insertion portion, in order to perform fluid supply control from the liquid supplying passage and air passage to the nozzle. In addition to the lens surface cleaning, there is the need to supply other fluids into the body. For example, when body fluids or other stains adhere to the walls of the body cavity, observation with the endoscope is difficult, and also in the event that there is a substantially great amount of adhesion, observation may be impossible. However, the nozzle for cleaning the lens surface is directed at a certain angle relative to the lens surface, i.e., in the direction across the field of view of the observation window, so spraying cleaning liquid from this direction cannot wash the body cavity wall to be observed. Accordingly, a jet spray aperture is opened at the distal end of the insertion portion for spraying fluid directly toward the direction of the observation field of the view of the observation window.
The fluid supplying passage for supplying fluid to the jet spray aperture is extended to the operating unit, and is connected to a pump connector provided to the operating unit. Detachably connected to this pump connector is a fluid pumping means, such as syringes or the like. Accordingly, a syringe, for example, consisting of an outer cylinder, a piston slidably provided within this outer cylinder, and an inner cylinder to cause the piston sliding movement within the outer cylinder is connected to the pump connector. Pushing the syringe piston into the outer cylinder supplies fluid or the like therein to the jet spray aperture.
Now, in order to perform jet spraying, the syringe or other pumping means must be operated manually. However, it is essentially impossible for a doctor or other operator rasping the operating unit of the endoscope to operate the fluid pumping means, and requires the assistance of a nurse or the like for this operation. It is known that cleaning liquid for the lens surface is supplied to the jet spraying aperture, such as disclosed in Japanese Unexamined Patent Application Publication No. 6-68717, so as to eliminate the need for assistance of a nurse or the like on jet spraying.
With this known fluid supplying apparatus, a three-way valve is provided to the operating unit, and a passage at the fluid source side and two passages consisting of a nozzle side and an aperture slide passages are each connected to the casing of the three-way valve. Then, the valve member of this three-way valve is mounted to the operating unit in a manner capable of being reciprocally rotated by a predetermined angle. Accordingly, rotating the valve member switches between a state wherein the fluid source passage is communicated to the nozzle side passage, and a stat wherein this is connected to the aperture side passage. Consequently, when stain or the like is adhered to the body cavity wall, by rotating the valve member of the three-way valve, the fluid source is connected to the jet spray aperture, thereby supplying the cleaning liquid from the fluid source to the jet spray aperture. Once the stain is removed from the body cavity wall, the valve member of the three-way valve may be operated to return to the state that the fluid source side is connected to the nozzle side for restoring a state wherein normal lens surface cleaning may be performed. Further, effectively removing stain adhered to the body cavity wall requires a pressure higher than that for lens surface cleaning, so with the above-described conventional art, the supplying pressure of the cleaning liquid from the fluid source is raised.
Now, the conditions for cleaning liquid supplying are not always the same for the above-described two states. That is, stain of the lens surface can often be easily removed with a smaller amount of cleaning liquid at a lower pressure, as compared to the removing of stain adhered to the body cavity wall. Further, the lens surface is constantly being soiled, so lens surface cleaning is repeatedly performed during operation. In the event that lens surface cleaning is performed at an unnecessarily high pressure, the amount of flow increases to force much pain to the patient. Accordingly, at the time of performing lens surface cleaning, the amount of cleaning liquid must be kept to an absolute minimum. On the other hand, a rather high pressure is necessary for jet spraying. Accordingly, the supplying pressure and supplying amount of cleaning liquid differs between lens surface cleaning and body cavity wall cleaning, so using the same fluid source is not necessarily desirable. However, depending on the state and the like of stain adhered to the lens surface, there are cases wherein spraying high-pressure cleaning liquid is desired. Thus, a configuration wherein selection can be made of spraying the cleaning liquid at a high pressure as necessary on cleaning the lens surface cleaning, is further preferable.
Also, the fluid supplied toward the body cavity wall is not limited to the above cleaning liquid, and for example, coloring agents or the like may be dispersed on or sprayed onto the body cavity wall. However, as described above, in the event that the configuration is such that the jet spray aperture is connected to the fluid source for lens surface cleaning liquids other than cleaning liquid cannot be supplied to the jet spray aperture. Accordingly, yet another fluid supplying passage must be provided in other to perform coloring agent dispersion, drug fumigation, etc.
The present invention has been made in light of the above points, and accordingly it is an object thereof to allow desire fluids to be supplied to the observation window and jet spray aperture at desired pressures and desired flows.
In order to achieve the above objects, according to the present invention, there is provided a fluid supplying apparatus for an endoscope, which comprises: an observation window provided at a distal end portion of an insertion portion; a nozzle for spraying at least a cleaning liquid toward the observation window; a first fluid supplying passage connected to the nozzle; a jet spray aperture formed to the distal end portion for spraying fluid in forward direction of the insertion portion; a second fluid supplying passage connected to the jet spray aperture; a control valve provided within a operating unit connected to the insertion portion, to which the first fluid supplying passage is connected; a casing for dividing the first fluid supplying passage into a nozzle side passage and a valve side passage, and to which the second fluid supplying passage is connected; a pump connector, provided within the casing, for detachably mounting a fluid pumping means and being formed a supplying passage for flowing fluid from the fluid pumping means; a switching passage provided to the pump connector, the switching passage being capable of switching between a first position wherein the nozzle side passage is connected to a valve side passage of the first fluid supplying passage and the supplying passage is cut off from the second fluid supplying passage, and a second position wherein the nozzle side passage is cut off from the valve side passage of the first fluid supplying passage and the supplying passage is connected to the second fluid supplying passage; and a check valve provided to the supplying passage for preventing flow from the switching passage side to the supplying passage side.
In this connection, the pump connector can be composed of a casing mounted to the operating unit to which are connected a nozzle side and a valve side passages in the first fluid supplying passage and a second fluid supplying passage, and a fluid pumping means connecting unit mounted in the casing to be detachably connected the fluid pumping means and having a switching passage and a supply passage provided with a check valve. The fluid pumping means connecting unit may be switched by its rotational operation of a predetermined angle within the casing to select the switching passage between a first position wherein the nozzle side passage is communicated to the valve side passage of the first fluid supplying passage, while the supplying passage is cut off from the second fluid supplying passage, and a second position wherein the nozzle side passage is cut off from the valve side passage of the first fluid supplying passage, while the supplying passage is connected to the second fluid supplying passage. In this case, the fluid pumping means connecting unit can be installed with click means for retaining these two selection positions for producing a suitable operation feeling. By constructing the fluid pumping means connecting unit movable along the axial line direction by a predetermined length within the casing and being provided a connecting passage, switching to a third selected position is further available to connect the valve side passage of the first fluid supplying passage with the second fluid supplying passage, while cutting off the nozzle side passage, thus enabling fluid to be supplied in four modes.
These and other objects, configurations, and advantages and the like of the present invention will become more apparent from the embodiments described below with reference to the drawings. It is needless to say that the present invention is not to be interpreted so as to be restricted to these embodiments.